The present invention relates to test strips of th type used to indicate by color properties with respect to a liquid such as urine in which the test strip is dipped. Also, the present invention relates to methods and apparatus for utilizing such test strips.
Thus, the present invention relates to a method and apparatus for measuring light-reflectivity of colorreaction reaction test paper utilized for various purposes such as testing of liquid samples such as urine, and the invention also relates to the construction of the test strip itself.
Color-reaction test papers are widely used as a simple means for analyzing liquids. For example in many hospitals and clinics it is conventional to utilize test papers for measuring, as a part of a clinical examination, concentrations of glucose, protein, pH, bilirubin, etc. in urine.
Thus, when such a test paper is dipped into a liquid such as urine, the test paper will have a color-reaction to an extent which will be indicative of the concentration of the particular liquid component which is to be measured. Judgment of the degree of color-reaction of the test paper is generally carried out by comparison with a color-reaction sample at a standard concentration of the liquid component which is to be measured. This comparison of tone utilizes only the naked-eye observation of skilled technicians. In many cases, particularly with complex test paper, it is necessary to carry out accurate comparison with corresponding color-reaction samples for each item. These operations are extremely troublesome because the tone of the color-reaction test paper piece often will change with the passage of time. Conventionally, the skilled technician will make a judgement in a relatively short time and will utilize his memory of the color-reaction tone as obtained through experience. However, such results are defective and highly inaccurate inasmuch as the judgment is influenced in a highly subjective manner according to the individual differences of the technicians who make the judgment. Thus it is impossible to achieve the desired degree of objectivity with such conventional procedures.
Moreover, due to the great increase in clinical examinations in recent years, there has been a large increase in the number of items and samples which must be measured, and thus the number of technicians available for carrying out these operations is far too small to meet the required demand. For such reasons it has become necessary to prove the efficiency with which the examination procedures are carried out as well as to save personnel.